Volume diverted by SCA for the urban holders during the 2010–11 year (ML)

Sydney Water Corporation

Cascades

4,551

Illawarra

28,976

Macarthur

24,437

Nepean

3,604

Orchard Hills

18,421

Prospect

316,385

Warragamba

1,039

Woronora

15,778

Shoalhaven City Council

Kangaroo Valley

71

Bamarang and Flat Rock

16,419

Wingecarribee Shire Council

Wingecarribee

3,477

Raw water to other retail customer

Not applicable

18

Unfiltered water to other retail customers

Not applicable

186

Total

433,362

The previous table is based on supply records of the bulk supplier, SCA. However, the water receivers, in the form of the Shoalhaven City Council, Sydney Water Corporation and Wingecarribee Shire Council, record differences in received volumes. The differences have been attributed to limits in meter accuracy. In order to maintain consistency in calculations, the previous table, as well as the accounting statements, show the volumes recorded by the bulk supplier.

Diversion of flows by other entitlement holders

Urban holder

Water treatment plant

Water diverted during the 2010–11 year (ML)

Goulburn Mulwaree Council

Goulburn

2,432

Lithgow City Council

Oakey Park

1,508

Wingecarribee Shire Council

Bundanoon

446

Medway

421

Total

4,807

The Fish River Water Supply Scheme delivered 506 ML to Lithgow City Council's distribution system within the Sydney region. This volume was not diverted from surface water sources in the Sydney region. Therefore, it is not included in the previous table, but instead included in line item 11.9 Delivery of water to urban system under inter-region agreement.

Quantification Approach

Goulburn Mulwaree Council

Data Source

Data spreadsheets.

Provided by

Goulburn Mulwaree Council.

Method

Diversions to the water treatment plants (WTPs) were measured at the plants. At Goulburn WTP, inflow from the plant was measured using a flow meter.

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume is based on metered data. Estimated accuracy based on meter accuracy and professional judgment is +/– 20%.

Lithgow City Council

Data Source

Data spreadsheets.

Provided by

Lithgow City Council.

Method

The flow diverted from Farmers Creek No. 2 Reservoir to Oakey Park WTP was measured by the height of the water over the weir in the channel at the inlet works at the WTP. There is a direct pipeline connection between the storage and the WTP. The outflow from the WTP was measured by an ABB Magflow meter.

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume is based on measured data. Estimated uncertainty based on meter accuracy is +/– 2%. Meters are calibrated annually by ABB (meter supplier).

Sydney Catchment Authority

Data Source

Provided by

Method

Full-bore magnetic flow meters and ultrasonic flow meters were used to measure water diversions to urban utilities.

Assumptions, Limitations, Caveats and Approximations

There are minor differences in the supplied volumes recorded by the SCA and its recipients. In order to maintain consistency, the values provided by the SCA have been used for this line item.

Uncertainty Information

The volume is based on measured data. Estimated accuracy based on meter accuracy is +/– 2%.

Wingecarribee Shire Council

Data Source

ABB Magflow meters based at raw-water pump stations, Supervisory Control and Data Acquisition (SCADA) system and Wingecarribee Shire Council data spreadsheets.

Provided by

Wingecarribee Shire Council.

Method

Volumes were derived from ABB Magflow meter data received through the SCADA system and transferred into spreadsheets.

Assumptions, Limitations, Caveats and Approximations

The quantification method used in this note only applies to the council's water diversions from Medway and Bundanoon storage reservoirs to their respective WTPs. Supplies to the council's Wingecarribee WTP are made by the SCA.

Uncertainty Information

The volume is based on measured data. Estimated accuracy based on meter accuracy is +/– 7%. External flow verification audits for the flow meters are conducted annually by Hydrometric Consulting Services.

Comparative year

The following table compares the value at 30 June 2010 reported in this account with the corresponding value reported in the 2010 Account.